1. Field of the Invention
The present invention relates to glycoprotein hormone analogs having altered receptor binding specificity and activity. Specifically, the invention pertains to alpha, beta-heterodimeric polypeptides having binding affinity to follicle stimulating hormone (FSH) receptors and luteinizing hormone (LH) receptors. The residues important for receptor binding and specificity are located between Cys93 and Cys100 and Cys100 and Cys110 of hCG. These residues correspond to hFSH residues 87-94 and 94-104. A wide variety of alpha, beta-heterodimeric polypeptides can be made to alter the LH and FSH receptor binding activity and specificity of the polypeptides without disrupting their abilities to form alpha, beta-heterodimers or react with antibodies. This invention also pertains to methods for preparing these alpha, beta-heterodimeric polypeptides and the pharmaceutical compositions in which they may be employed.